Electric step-by-step motor of the unwound-armature type



J. W. FR E N C H.

ELECTRIC STEP-BY-STEP MOTOR 0F THE UNWOUND ARMATURE TYPE.

mso MAR.30,1921. 2 SHEETS-SHEET 1.

Jan. 2, 1923. 1,440,729.

ELECTRIC STEP-BY-STEP MOTOR 0F THE UNWOUND ARMATURE TYPE.

J. W. FRENCH.

2 SHEETS SHEET 2 FILED MAR. 30, T921.

t l p 1 v F/Gf.

me am M Patented Jan. 2, 1923.

UNITED STATES PATENT OFFICE. l

JAMES WEIR FRENCH. OF GLASGOW, SCOTLAND, ASSIGNOR TO BAE?. AND STROUD, LIMITED, OF GLASGOW, SCOTLAND.

ELECTRIC STEP-BY-STEP MOTOR OF THE UNWOUNZRARQMATURE TYPE.

Application led March 30, 1921,.

T0 alf. whom 'it may concern.'

Be it known that I, JAMES Wnm FRENCH, a subject ot' the King of Great Britain and Ireland, and ot' Caxton Street, Anniesland, Glasgow, Scotland, have invented new and useful Im} novements.in or Connected With Electric Step-by-Step Motors of the Unwound-Armature Type, of which the following is a specification.

This invention, which refers to electric Istep-by-step motors ofthe unwound armature type, consists'in the production of an improved, type of motor having-` at least three motor-elements, each motor-element comprising an electro-magnet and an un- Wound rotary armature each having a circular series of complementary pole faces concentrically arran ed and disposed at equal angles apart, andg a coil composed of circular windings about the pole faces of the magnet concentric to the axis of the motorelement, in which the armatures of the motor are connected to rotate together, and in which the relative disposition of the pole faces of the motor-elements is such that when the complementary pole faces of one motorelement are in angular conformity those of the other motor-elements are in angular disconformity, but in the process of operation come into conformity successively.

In construction, the armature of a motor- 'element may be arranged to occupy a position within` or without its electro-magnet, and the armatures and electro-magnets associated to form a motor may be arranged with their pole faces concentric to one and the same axis, or about separate axes one for each motor-element.

In the case of a motor comprising, say, three motor-elements so arranged that the pole -i'aces of thethree motor-elements are concentric to one and the same axis, the pole vfaces of the threel armatures may be in alignment parallel with the axis, in which case the complementary pole faces of the respective electro-magnets would be disposed at equal angles about the axis, or the pole faces of the three electro-magnets may be in alignment and the complementary pole faces oi' the respective armatures be disposed at equal angles apart. These arrangements have con structional advantages but the condition required may be obtained in which the pole faces of both series are each angularly disposed.

Serial Nc. 46? ma.

Some examples of construction will now be described with reference to the accom panying drawings, in which Figure l is an elevation partly in section. Figure 2 is a cross section and Figure 55 is a vertical section illust-rating one form of. construction.

, Figure 4 is a vertical section and I`igurc` 5 is a plan partly in section illustrating an@ other. construction.

Figure 6 is a. sectional elevation and Figure 7 is a plan illustrating a further construction.

The motors illustrated in each const-ruction comprise the provision of three motorelements and are intended for the production. of rotary step-by-step motion in one or either direction.

In the motor illustrated at Figures 1, .2 and 3, A, A, A are the armatures which are fixed to a shaft B and rotate therewith. In

4this construction the armatures shown are of hollow cylindrical form and the shaft B is composed of two parts which fit one into each end of the bore. Each armature A is formed with a` circular series of pole faces l., see Figure i2. C, C, are the electro-magnets each of whichy is formed with a circular series of pole faces 2, sce Figure 2. I) lf), l)

are the coils of the magnets` composed of circular windings ctmcentric to the axis of the shaft B. The electro-magnets (l are con tained within a Stationary casing E and may be fixed against rotation` for instance, by longitudinal key and slot connection with the casing. In the wmstruction illustrated the casing lfl is open at one end and is 't'ornled with a cylindrical interior to receive the electro-magnets C. each et which comprizezes two Darts 53. 4, of annular ik' 'in whicl'l are applied ondwise trom oppoe onto its` coil I). The electro-magnet. auf?, the armatures with the shaft B are adapted to be assembled within the ca.AA 1.., duction 'from the open cui here( tained by a cover f ringy cap lill screwed onto g l" whim in the process, of appiic., on operates to forca the Darts: endwiso iolcther. (lne hear,- ing for the araY head ot' the casing the otlicr in the cover IC.

In the construction illustrated at Figures #i and 5 the electro-inagnets if". laire cxlcrnal pole faces 2, and are ilxcd upon a stationary shaft 3 which is carried bj.' :i littv .l curul bv a 6. The armatures, designated generally A1, which as shown may be formed in one part, consist of a cylindrical sleeve having internal pole faces 1` The armatures in this case are fixed to carriers 7 and 8 which are mounted to rotate on journals formed on the shaft'. Each electro-magnet in this con struction also comprises two parts 3, 4. of annular form which are applied endwise onto its coil D.

In the construction illustrated at Figures 6 and 7, the motor-elements areA arranged each about a separate axis. In this case the armatures A2, which are arranged each Within an electro-magnet C, are geared together to rotate a'shaft B1, for which purpose each armature is provided with a gear wheel F arranged to gear With a toothed wheel B2 fixed on the shaft B1..k

For operating these motors provision is made whereby the electro-magnets are energized successively in pairs or separately.

The pole faces, which need not be parallel with the axisof rotation, may be of various forms.

In the constructions illustrated the pole faces of the magnets extend from parts 3 and t of complete annular form, which, how ever, need not be circular. Further, the pole faces of the magnets are arranged to extend longitudinally and'in each electro-magnet are situated between the two planes, per-- pendicular to the axis of the pole faces, which contain the ends of its coil.

l claim l 1. An electric step-by-step motor having at least three motor-elements, each motor- Ielement comprising an electro-magnet and an unwound rotary armature each having a circular series of complementary pole faces concentrically arranged and disposed at equal anglesapart and a coil composed of circular windings about the pole faces of the magnet concentric to the axis of the motorelement, in which the armatures of the motor are connected to rotate together9 and in which the relative disposition of the pole faces of the motor-elements is such that when the complementary pole faces of one motoreelement are i-n angular conformity those of the other motor-elements are in an gular disconformity but in the process of operation come into conformity successively.

2. An electric step-by-step motor having at least three motor-elements, each motorelement comprising an electro-magnet and an unwound rotary armature arranged within its electromagnet,u each having a circular series of complementary pole faces concentrically arranged and disposed at equal angles apart and a coil composed of circular windings about the pole faces of the magnet concentric to the axis of the motor, the pole faces of the magnets extending' longitudinally and situated between the two planes,

Madras perpendicular to the axis of the pole faces, which contain the ends ofits coil, in which the armatures of the motor are connected to rotate together, and in which the relative disposition of the pole faces of the motorelements is such that when the complementary pole faces of one motor element are in angular conformity those of the other motor-elements are in angular disconformity but in the process of operation come into conformity successively.

3. An electric step-by-step motor having at least three motor-elements, each motorele ment comprising an electro-magnet and an unwound rotary armature7 each having a circular series of complementary pole faces concentrically arranged andA disposed at equal angles apart and a coil composed of circular windings about thepole faces of the magnet concentric to t-he axis of the motor, the pole faces of the magnets extending longitudinally and situated between the two planes, perpendicular to the axis of the ole faces, which contain the ends of its coi in which the armatures of the motor are connected to rotate together and arrangedwith their polefaces concentric to one and the same axis, and in which the relative disposition of the pole faces of the motorelements is such that when the complementary pole faces of one motor-element are in angular conformity those of the other motor-ele ments are in angular disconformity but in the process of operation come into conformity successively.

Ll. An electric step-by-step motor having at least three motor-elements, each motorelement comprising an electro-magnet and an unwound rotary armature arranged With in its electro-magnet, each having a circular seriesof complementary pole faces concentrically arranged and disposed at equal angles apart and a coil composed of circular windings about the pole faces of the magnet concentric to the axis of the motor, the pole faces of the magnets extending longitudinally and situated between the two planes, y

perpendicular to the axis of the pole faces, which contain the ends of its coil, in which the armatures of the motor are connected to rotate together and arranged with their pole faces concentric to one and the same axis, and in which the relative disposition of the pole faces of the motorelements is such that when the complementary pole faces of one motor-element are in angular conformity those of the other motor-elements are in anguiar disconformity but in the process of operation come into conformity successively.

5. An electric step-by-step motor having at least three motor-elements, each motor-element comprising an electro-magnet and an unwound rotary armature, each having a circular' series of complementary pole faces concentrically arranged and disposed at coil, in which the armatures of the motor uro are connected to rotate together and ar` ranged with their pole faces concentric to one and the same axls, and 1n which the pole faces of the armatures are in align-- ment and the respective series of pole faces of the electro-magnets are disposed at equal angles apart, and the relative disposition of the pole faces of the motor-elements is such that when the complementary pole faces 'of one motor-element are in angular conformity those of the other motor-elements are in angular disconformity but in the process of operation come into conformity successivel 6. An e ectric step-by-step motor having three motor-elements, each motor-element comprising an lectro-magnet and an unwound rotary armature each having a circular series of complementary pole faces concentrically arranged and disposed at equal angles apart and a coil composed of circular windings about the pole faces of the magnet concentric to the axis of the kmotor-element, in which the armatures of the motor are connected to rotate together, the pole faces of the magnets extending from parts of complete annular form, and in which the relative disposition of the ole faces of the motor-elements is such that w en the complementary pole faces of one motorelement are in angular conformity those of the other motorfelements are in angular disconformity but in the process of operation come into conformity successively.

7. An electric step-by-step motor having three motor-elements, each motor-element comprising an electro-magnet and an unwound rotary armature arranged Within its electro-magnet, each having a circular series of complementary l pole faces concentrically arranged and disposed at equal angles apart and a coil composed of circularl windings about the le faces of the magnet concentric to the axis of the motor, in which the armatures of the motor are connectedto rotate together, the pole faces of the magnets extending from parts of complete annular form, and inl which the relative disposition of the pole faces of the motor-elements is suchthat when the complementary pole faces of one motor-element are in angular conformity those of the other motor-elements are in angular disconformity but in the process of operation comprising an electro-magnet and an un Wound rotary armature, each having a circular series of complementary pole faces concentrically arranged and disposed at equal angles apart and a coil composed of circular windings about the pole faces of the magnet concentric to the axis of the motor, in which the armatures of the motor are connected to rotate together and arranged with their pole faces concentric to one and the same axis, the pole faces of the magnets extending from parts of complete annular form, and in which the relative disposition of the pole faces of the motor elements is such that when the complementary pole faces of one motor-element are in angular conformity those of the other motor-ele- .ments are in angular disconformity but in `ity successively.

9. An electric step-by-step motor having three motor-elements, each motor-element comprising an electro-magnet and an unwound rotary armature'arranged within its electro-magnet, each having a circular series of complementary pole faces concentrically arranged and disposed at equal angles apart, and a coil composed of circular windings about the pole faces of the magnet concentric to the axis of the motor,'in which the armatures of the motor are connected to rotate together and arranged with their pole faces concentric to. one and the same axis, the pole faces of the magnets extending from parts of complete annular form, and in which the relative disposition of the pole faces of the motor-elements is such that When the complementary pole faces of one motor-element are in angular conformity those of the other motor-elements are in angular disconformity but in the process of operation come into conformity successively.

10. Anelectric step-by-step motor having three motor-elements, each motor-element comprising an electro-magnet and an un' wound rotary armature, each having a circular series of complementary pole faces -concentrically arranged and disposed at equal angles apart and a coil composed of circular windings about the pole faces of the m et concentric to the axis of the' motor, 1n which the armatures of the motor lare connected to rotate together and arranged With their pole faces concentric to one and the same axis, the pole faces of the magnets extending from parts of complete annular form, and in whlch the pole faces of the armatures are in alignment and the respective series of pole faces of t-he electromagnets are disposed at equal angles apart, and the relative disposition of thevpole faces of the motor-elements is such that when the complementary pole faces of one motor-element are in angular conformity those of the other motor-elements are in angular disconformity butin the process oi"- opei'ation come into conformity successively..

l1. An electric stepl ystep motor having at least three motor-elements, each motorelenient comprising an electroqnagrnet and an unwound rotary aimatul'e, each having ay circular series of cou'iplementary pole faces concentiically arreugfxl and disposed at equal angles apart and a coil composed of circular windings about the pole faces of the magnet, concentric to the anis o'l' the inotoi', in which the armatures of' the motor are connected, to 'notate together and an ranged with theizf pole faces ':oncenti'c to one and the same axis, the pole faces of the magnets extending from parts of complete annular form, and in which the relative disposition of the pole faces of the motor-eleA ments is such that When the complementary pole l'aces of one inotonelement are in ang lai` confomity those of the other motoreilements are in angular olisconformity but, in the process of operation come into conformity successively, in combination with a sta* tionai'y casing formed with a cylindrical ini teioi to receive the electro-magnets and the armatures, substantially as setl foith.

,cames l2. An electric step-by-step motor having three 1noto1-elen1ents, each motoieelement comprising an electro-magnet and an un- Wound rotary armature, each having a cil'- cula-r series of complementary pole faces concentrically arranged and disposed at. equal angles apart and a coil composed of circular windings about the pole faces of the magnet conccntL-ic to the axis of the motor, in which the armatures of the motor are connected to rotate together and arranged with their pole faces concentric to one and the seme axis, the pole faces of the magnets' extending from parts of complete annular forni, and in which they relative disn position of the pole faces of the motor-elo ments is such that.. when the complementary pole faces of one motor-element are in engulm conformity those of the' 'other motor- 'elenients are in angulal disconfoirnity but in the process of opera-tion come into conformity successively, in combination with a stationary casing formed with a cylindricalinterlor 'to receive che electro-magnets and the armatures, substantially as set forth.

JAMES Weissensee.

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